Makefile: refactor to use browserify
Makefile: refactor to use browserify

Uses browserify to build a `dist/debug.js` file for
standalone browser-side consumption.

elliottsj/debug,elliottsj/debug,zacronos/debug,jabaz/debug,CantemoInternal/debug,jabaz/debug,zacronos/debug,CantemoInternal/debug,visionmedia/debug